Re: Would you open a rare single malt
Sell it. Buy copious amounts of whisky that is delicious but not price-inflated due to rarity. (Maybe get a little something for the wife too.) The rarity doesn't make it taste any better.
This is my inner economist talking, but the decision is the same as whether you would BUY such a bottle for the same price. In your left hand you have Bottle X. In your right, a small pile of cash. Which do you prefer to walk away with?
If you would buy and drink a very expensive bottle (as clearly some here would), then go for it. Drink that dusty gem that Grandpa left behind. If you wouldn't, then cash out.
It's like when people on Antiques Roadshow find out that some attic dust collector is worth big money. Do they sell it? I don't know, but I always think they should. Unless you would BUY a $4500 early American handmade chair (or whatever), you probably value the cash more than the item. Get the cash.
That said, if any of my friends stumble upon a delicious rare old bottle, they should clearly open & share!